function Person(name, age) {
    this.name = name,
    this.age = age,
    this.play = [1, 2, 3]
    this.setName = function () { 
        console.log('进来')
    }
}
Person.prototype.setAge = function () { 
    console.log('年龄')
}
//子类型
function Student(price) {
    this.price = price
    this.setScore = function () { }
}
Student.prototype = new Person() // 子类型的原型为父类型的一个实例对象
var s1 = new Student(15000)
var s2 = new Student(14000)
console.log(s1)
console.log(s1.setAge())